Protective films are attached to all products, such as various display products and general electronic appliances, including mobile phones, notebooks, and cosmetic cases, which are released from factories to protect the products. Such a protective film require a strength and a bonding property according to a product, and it is preferable that the protective film is formed of a transparent material so as not to damage an external appearance of the product in addition to an aspect of the product. It is preferable that an adhesive is not stuck to a product, that is, the adhesive is not transferred to the product after the protective film is removed.
In addition, in recent years, problems due to harmful substances emitted from various chemical products have been social issues, and development of environment-friendly materials which do not emit harmful substances is urgent in the field of product protective film.
According to the related art, PVC, PE, and PP films and acryl or a silicon resin are used as a product protective film. However, since a large amount of chlorine substances is detected from the PVC film, it appears that use of the PVC film will be limited. When a conventional acryl adhesive is used, an afterimage may be left on a surface and bubbles may be generated. Further, bonding force also may be problematic. General PP is transparent but is not flexible due to material characteristic thereof, and thus there is a limit in using general PP on convexo-concave surfaces or curved surfaces.
Further, various functional cosmetics having various functions, such as a skin whitening function, a skin wrinkle prevention function, and a hair follicle reduction function, have recently released. Because the functional cosmetics are not chemically stable against heat or light, cosmetic contents cannot be smoothly protected so that the cosmetic contents may be modified if PVC, PE, PP films, acryl or a silicon resin is used as an adhesive.
That is, if functional cosmetics is preserved while a suitable protective film is not applied to a surface of the functional cosmetics, cosmetic contents may be modified so that effectiveness deteriorates, and as the modified contents are converted into a functional material having a strong stimulus, a skin trouble may be caused.